Warm greetings from Malaysia

Hi everyone, I am Serene Low, a newbie from Malaysia. I started vegetable planting about 4 months ago and finally I am beginning to see a few green beans and one bell pepper growing on my container plants. My spring onions are growing tall and about time to be harvested for the 6th round. I recently harvested my sweet basil and had cut and dipped 3 stalks of it in water for rooting and replanting purpose. My chilli plants are not growing well at all as most of the leaves are withering. I live in a hot tropical and humid country where temperature is normally between 26 C to 32 C with seasonal rainfall throughout the year. I wonder what is wrong with my chilli plants???